Chapter 1 Flashcards
Where does the word atom come from?
atomos (greek) meaning indivisible
What is the first step of the scientific method?
make observations and collect data
What is the second step in the scientific method?
suggest explanations (hypothesis)
What is the third step in the scientific method?
conduct experiments (testing explanations)
What is the last step of the scientific method?
come to a conclusion using the results of your experiment
To verify the results of the experiments, what do scientists usually do?
repeat the experiment multiples times to verify the results
What is natural law?
Natural law is an observation applicable to many systems (ex. the law of conservation of mass)
What is the law of conservation of mass?
Matter can neither be created nor destroyed
What is a theory?
a theory is a set of tested hypotheses that explain a phenomenon (ex. atomic theory)
What is the law of definite proportion?
compounds always contain the same proportions of elements by mass
What was the first “type” of chemistry that humans practiced?
alchemy, a pseudoscience
What is the phlogiston theory?
the spirit of materials being burned that is stuck to the fire is what makes the ashes lighter than the wood and also taking away mass
What did Antoine Lavoisier do/find?
Antoine burned logs in a closed container and found that the mass still stayed the same, some just got turned into a gas
In Dalton’s atomic theory, the first law states that
each element is made up of tiny particles called atoms
In Dalton’s atomic theory, the second law states that
atoms of a given element are identical
In Dalton’s atomic theory, the third law states that
chemical compounds are formed when atoms from different elements combine
In Dalton’s atomic theory, the fourth law states that
chemical reactions involve the reorganization of atoms
What did J.J Thompson study?
studied electrical charges in a cathode-ray tube
How did J.J. Thompson set up his experiment?
There was a positively charged magnet on one end of the cathode ray and the negatively charged magnet on the other end of the cathode ray, the stream of electrons gravitated towards the positive magnet
What did J.J Thompson conclude from his experiment?
particles were negatively charged components of atoms and that electrons were just floating around a cloud of positive atoms (plum pudding model)
What did Robert Millikan study?
the size of an electron
How did Robert Millikan set up his experiment?
the different sizes of oil droplets floating between the positive a negative plates
What did Robert Millikan conclude from his experiment?
the size of the oil droplets led to the conclusion that the size of an electron is 1.6x10^-19
What did Rutherford study?
the charges within an atom
How did Rutherford set up his experiment?
he shot alpha particles (+) at a gold fold and watched to see the alpha particles pass through since it was thought that there were a cloud of positive atoms in the structure of an atom
What did Rutherfurd conclude from his experiment?
he concluded that since some of the alpha particles deflected from the gold foil, that meant there was a dense positive core in atoms
all matter is composed of ____
all matter is composed of atoms
What are diatomic elements?
diatomic elements are elements that naturally exist as molecules (2 or more atoms covalently bonded, ex. hydrogen, oxygen, nitrogen etc..)
What are the diatomic elements?
H - hydrogen O - oxygen F - fluorine N - nitrogen Cl - chlorine I - iodine Br - bromine
Where is the proton found?
in the nucleus
Where are neutrons found?
in the nucleus
Where is the electron found?
outside the nucleus
______ and ______ have the same mass
protons and neutrons have the same mass
____ and ____ have _____ charges with equal magnitude
protons and electrons have opposite charges with equal magnitude
What determines the chemical properties of an atom?
The number of electrons they have and their arrangement
What are the three types of radioactive emissions?
gamma rays, beta particles, alpha particles
gamma rays have ____ energy in the form of ____
gamma rays have high energy in the form of light
beta particles have _____
beta particles high-speed electrons
alpha particles posses ____
alpha particles posses 2 postive charges
The number to the upper left-hand side of the elemental symbol is called
the mass number
What does the mass number consist of?
Protons + neutrons
The number to the lower-left hand side of the elemental symbol is called
the atomic number
What does the atomic number consist of?
the number of protons an elemental atom has
What are isotopes?
atoms with the same number of protons and electrons, but different amounts of neutrons
What are ions?
when atoms gain or lose an electron, the atoms become charged with either + or -
